Round 12 Survey Specification published

The Survey Specification for Round 12 of the European Social Survey (ESS) - due to be fielded across Europe in 2025/26 - outlines the beginning of a data collection mode transition.

The Survey Specification for ESS ERIC Member, Observer and Guest Countries includes the tasks and responsibilities required of national teams to conduct the survey to the highest possible methodological standards.

There are some major changes from the Survey Specification for Round 11 (2023/24), currently being fielded in 31 participating countries.

The first key difference relates to the mode of data collection. Round 11 is being conducted in line with rounds 1-9, using face-to-face interviews.

Countries will be expected to conduct Round 12 fieldwork using a mixed method approach: half the sample will be interviewed in person and the other half will complete the questionnaire via web and postal modes.

This change is being implemented ahead of the move to only self-completion modes in Round 13 (2027/28) of the survey.

It was recommended by the ESS Methods Advisory Board (MAB) that countries conduct Round 12 face-to-face and self-completion fieldwork simultaneously to help better understand data collection mode effects. 

This built upon an earlier suggestion from an ESS strategic review that embedded experiments should be used during the data collection mode transition. 

To reflect the additional mode of data collection, the Round 12 Survey Specification also requests that national teams increase the amount of time they are able to spend on fielding the ESS.

The web and paper self-completion instruments will be provided centrally by Centerdata and use of these central tools is a mandatory requirement.

All countries will also be required to use Centerdata’s translation platform for both their face-to-face and self-completion translations.

Other Round 12 requirements include:

• National teams that do not have evidence that they can deliver the self-completion approach effectively must carry out a feasibility test prior to main stage Round 12 data collection. 
• Field workers that are used for the self-completion approach should receive an in-person briefing to train them in their role. 
• For the self-completion approach, national teams using a postal first method are required to offer an unconditional monetary incentive. A significant non-monetary incentive will be offered if there are any barriers in offering a monetary one.
• To tackle non-response in countries using the postal first approach and an address-based sample, national teams will need to use field workers to make in person visits to non-responders.
• National teams will need to deliver a combined main data file to the ESS Data Archive including all interviews across face-to-face and self-completion approaches. It is expected that separate contact data files will need to be prepared for each approach.
• Paper self-completion questionnaires must either be keyed manually into a data entry or scanned then merged with the web data.

Professor Rory Fitzgerald, Director of the ESS ERIC, said: 

“The ESS is undergoing a major transformation moving from face to face to self-completion data collection.

“The mixed method approach in Round 12 outlined in the survey specification will help current and future users understand the impact of the switch on our time series.

“It will also help to ensure a smooth transition as our national teams work to ensure the best self-completion design for the future. 

“Whilst there are significant challenges to switching mode across around 30 European countries, the ESS infrastructure will ensure it is as successful as possible.”

These tasks and responsibilities will be undertaken by the national coordinating team and by any survey agency appointed in each participating country.

The aim of the specifications is to ensure that high quality data are collected in a comparable way in each participating country.

Round 12 fieldwork is due to begin in September 2025.